Which one of the following processes during decomposition is correctly described?

(1) Leaching-Water soluble inorganic nutrients rise to the top layers of soil

(2) Humification-Leads to the accumulation of a dark coloured substance humus which undergoes microbial action at every fast rate

(3) Fragmentation-Carried out by organisms such as earthworm

(4) Catabolism-Last step decomposition under fully anaerobic condition